Belhadi, Ahfouda, Abdelouahab Mansour, and Abdelouahab Salmi. “Some Drazin Invertible Elements in Banach Algebras and Applications to Operator Equations Solutions”. Italian Journal of Pure and Applied Mathematics 42 (July 30, 2019): 428–435. Accessed October 27, 2026. https://journals.uniurb.it/index.php/ijpam/article/view/7224.